A Natural Solution for California's Herds: African Catfish Peptides

California's cattle producers and agricultural communities are all too familiar with the rising challenge of antibiotic resistance, making common bacterial infections harder to treat in livestock. But imagine a future where we could tackle these infections with a natural, powerful alternative. Our research points to just that: antimicrobial peptides (AMPs) found in African catfish.

We're really excited about these peptides because African catfish thrive in pathogen-rich freshwater, naturally producing these robust immune compounds in their skin mucus as a defense. This natural origin makes them highly appealing alternatives to synthetic drugs.

Predicted Safety and Potent Action

One of the most compelling aspects of these AMPs is their predicted safety for mammals. Our initial computer analyses suggest that various catfish AMPs are generally recognized as safe (GRAS). We predict they'll be absorbed in the human intestine without causing liver, brain, or heart toxicity. Furthermore, lab tests on a promising peptide, NACAP-II, confirmed it was non-hemolytic, meaning it didn't damage rabbit red blood cells—a strong indicator of its potential safety for mammalian cells.

Beyond safety, these peptides demonstrate effectiveness against problematic bacteria. One study revealed NACAP-II's strong activity against Extended-Spectrum Beta-Lactamase (ESBL)-producing Escherichia coli—a critical concern for both animal and human health due to its resistance to many common antibiotics. Another peptide, ACAP-IV, also showed antibacterial activity against E. coli and Staphylococcus aureus. We believe these AMPs work by directly disrupting bacterial cell membranes, a mechanism that makes it harder for bacteria to develop resistance compared to how they resist traditional antibiotics.

Asian Citrus Psyllid Distribution and Management: Page

Resources for Home Gardeners

WEB SITES and ARTICLES UC IPM Quick Tip Citrus Pest and Disease Prevention Program web site: CaliforniaCitrusThreat UCIPM: Pest note for ACP and HLB UC IPM: Quick tip for ACP and HLB VIDEOS UCR Elizabeth Grafton-Cardwell discusses the Asian citrus psyllid and HLB (2011) UC Riverside Scientists relea...
View Page
Asian Citrus Psyllid Distribution and Management: Page

Residential ACP Management Strategy

Asian citrus psyllid nymphs and adult (inset) on citrus shoot. Photo: M. Lewis, UC Riverside The Asian citrus psyllid (ACP) is widely established in both commercial and residential citrus throughout Southern California. Large-scale eradication of ACP in these environments is not feasible.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Grower Management

If psyllid is new to an area, then an eradication strategy is the best approach to managing the psyllid.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Grower Options

Map Use the Interactive Mapping Tool to locate your orchard and determine proximity to ACP and HLB detections as well as quarantine and treatment areas.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Home Gardeners

Map Use the Interactive Map to locate your residence and determine the Asian citrus psyllid (ACP) and huanglongbing (HLB) risk in your area.
View Page
Asian Citrus Psyllid Distribution and Management: Page

What am I looking for?

The Asian citrus psyllid adult is tiny - the size of an aphid. The wings are brown along the edge, with a clear gap along the back edge. The psyllid feeds with its rear end tilted up at a 45o angle, making the insect appear almost thorn-like on leaves and stems.
View Page
Asian Citrus Psyllid Distribution and Management: Page

How do I look for it?

How do I find psyllids? Check your citrus trees monthly. Whenever you see tiny new leaves forming (leaf flush), look closely for signs of the psyllid. Remember the adults fly and so they may be hard to observe and the eggs are so tiny they are hard to see without a hand lens.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Biological control

Tamarixia wasp parasitoid. Photo: M. Lewis The Asian citrus psyllid is attacked by many natural enemies, including lady beetles, lacewing larvae, syrphid larvae, minute pirate bugs, parasitic wasps, spiders, and birds.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Insecticidal control

Soil application of systemic insecticide by licensed applicator for sustained control of ACP.
View Page
Asian Citrus Psyllid Distribution and Management: Page

Eradication strategy

Principles for treating commercial citrus orchards following the first appearance of ACP or where aggressive action is being taken in HLB quarantine areas: Apply two ACP effective insecticides with different modes of action as soon as possible after detection of ACP, with at least one from the broad...
View Page